The present invention relates to a novel compound which has antitumor effects and is useful as a medicine, to a process for producing the same, and to microorganisms producing the substance.
Known examples of a macrolide having two or more oxazole rings include Ulapualide A and B (Journal of American Chemical Society, 108, 846-847, 1986) which are extracted from nudibranches and have antitumor activities, and Kabiramide C (Journal of American Chemical Society, 108, 847-849, 1986) which is also extracted from nudibranches and has antifungal effects.
An object of the present invention is to obtain, using a microorganism, a novel compound which has antitumor effects and is useful as a medicine, a process for producing the same, and microorganisms capable of producing the novel compound which has antitumor effects.
The inventors of the present invention have studied various compounds produced by microorganisms and found that a substance having antitumor activities was produced in a culture broth of 3533-SV4 strain which belongs to the genus Streptomyces. Subsequently, the inventors succeeded in isolating the active substance, determined its physicochemical properties and structure, and verified its antitumor effects, to thereby accomplish the present invention.
The present invention provides a compound of the following formula (1). 
The above compound is hereinafter referred to as xe2x80x9cSubstance GM-95xe2x80x9d.
The present invention further provides a process for producing Substance GM-95 which comprises cultivating a microorganism belonging to the genus Streptomyces and capable of producing Substance GM-95 in a culture medium, and isolating the substance from the resultant culture broth.
The present invention further provides a medicine and an antitumor agent comprising Substance GM-95 as an active ingredient.
The present invention further provides a pharmaceutical composition comprising Substance GM-95 and a pharmaceutically acceptable carrier therefor.
The present invention further provides a method of treating tumors which comprises administering an effective amount of Substance GM-95 to a patients.
The present invention further provides a use of Substance GM-95 for a medicine.
Furthermore, the present invention provides microorganisms capable of producing Substance GM-95, more specifically the microorganisms belonging to the genus Streptomyces.